Q1.Consider the experiment of throwing a die, if a multiple of 3 comes up, throw the die again and if any other number comes, toss a coin. Find the conditional probability of the event ‘the coin shows a tail’, given that ‘at least one die shows a 3’.
Answer : Option CExplaination / Solution: S = {(3,1), (3,2), (3,3), (3,4), (3,5), (3,6), (6,1), (6,2), (6,3), (6,4), (6,5), (6,6), (1,H), (2,H), (4,H), (5,H), (1,T), (2,T), (4,T), (5,T)} Let A = event that coin shows a tail. i.e. A = { (1,T), (2,T), (4,T), (5,T)} and B = event that atleast one die shows 3. B = {(3,1), (3,2), (3,3), (3,4), (3,5), (3,6),(6,3)}
Q4.The greatest positive integer , which divides n ( n + 1 ) ( n + 2 ) ( n + 3 ) for all n ∈N , is
Answer : Option CExplaination / Solution: If n = 1 then the statement becomes 1x2x3x4= 24 : the consecutive natural numbers when substituted will be multiples of 24.
Q6.The number of arrangements of n different things taken r at a time which exclude a particular thing is
Answer : Option CExplaination / Solution: The number of arrangements of n different things taken r at a time which exclude a particular thing is n-1Pr = P(n-1,r)
Answer : Option AExplaination / Solution: Order = 3 ,Since the highest order derivative is y′′′ but degree cannot be defined ,because the deriative term y’ is present in exponential form.
Answer : Option AExplaination / Solution:
Angle between skew lines is the angle between two intersecting lines drawn from any point parallel to each of the skew lines .